Manhole construction



April 24, 1934. J A JENSEN 1,956,423

MANHOLE CONSTRUCTION Filed Jan. 5. 1932 2 Sheets-Sheet l 1N VEN TOR.- Jamesflizwem Patented Apr. 24, 1934 TTES MANHOLE CON$TRUCTION Application January 5, 1932, Serial No. 584,848

Claims.

This invention relates to manhole construction.

In suitable forms of embodiment, it affords a simple, inexpensive, compact construction, that can be installed in a small compartment to permit 5 entry into a tank from such compartment. It is also well adapted for truck tanks, and for other containers. It may include a filling opening with a cover, cap, or filler plug that can be opened and closed very easily and quickly, and can easily be made quite tight when closed. The invention here shown is embodied in an oval manhole, but is equally adaptable to circular manholes.

In the drawings, Fig. I is a side elevation of a manhole construction conveniently embodying the invention, partly in vertical section.

Fig. II is a plan View, with part of the removable cover broken away.

Fig. III is a fragmentary side elevation, on a larger scale than Fig. I, partlyin vertical section.

Fig. IV is a perspective view of a cover-fastening device.

Fig. V is a perspective view of the removable cover, detached and inverted.

In Fig. I, the manhole structure is shown mounted in an opening in a tank wall 9, which is turned or flanged upward at to fit around the manhole frame or band 11. The upper edge of the tank flange 10 is welded to the exterior of the band 11 at 12, thus securing the latter and -making a fluid-tight joint. The frame 11 may be constructed of a flat band of heavy sheet metal bent to shape, with its ends welded together. The frame 11 should preferably fit (before welding) in its opening in the tank wall. As shown -in Fig. I, the frame 11 is of such width and so located, vertically or axially of its opening, as to project down into the tank below its wall 9 somewhat. The upper edge of the frame 11 is preferably finished flat and true, to seat and make 4.0 a tight joint with the superjacent main cover 14.

The lower portion of the frame 11 preferably has openings 15, shown as notches in its lower edge,

to take securing devices 16 for holding the cover 14.

4.5- The main cover 14 is shown as of inverted 'saucer shape, with a thickened downturned outer edge or margin 17, and an upstanding (externally screw-threaded) flange or neck 18 around its central (circular) filling opening, also thickened at its top 19. As shown, the thickened edges 17, '19 are grooved to accommodate (soft) gaskets 20, 21, that engage and make tight joints with the upper edge of the frame 11 and with the filler plug, cap, or cover 22. Between the flange 18 55 and the margin 17, the cover 14 has openings for the securing devices or anchors 16, with flattopped bosses 23 around them. The anchors 16 consist of hook bolts whose headed lower ends 24 hook under the frame 11 and engage in the frame notches 15, while their threaded upper ends ex- 9 tend through the cover holes and have cap or acorn nuts (or heads) 25 that seat on the bosses 23,-copper washers 26 or the like being preferably interposed to make tight joints between the main cover 14 and the cap nuts 25. 5 The main cover 14 is preferably made of malleable iron, pressed steel, or the like.

The filling cover 22 is preferably hinged to the frame 11, as by hinge lugs 27 that cooperate with upstanding hinge lugs 28 on the main cover 14, and a pintle 29. The cover 22 may be provided with a standard vent valve 29a, if desired. The cover 22 is shown as of inverted saucer shape, with a machined surface (ridge) 30 to bear on the gasket 21. The overhanging margin 31 of the cover 22 cooperates with a securing device on the main cover 14, consisting of a rotary locking ring 33 threaded on the neck 18, and provided with operating arms or handles 34 for convenience in turning it. These handles 34slope radially upward and outward, so as to move and clear between the cover edge 31 and the bolt heads or nuts 25. As shown in the drawings, the cover margin 31 has an inward extending mutilated flange or series of lugs 35, and the locking ring 33 has a corresponding external mutilated flange or series of lugs 36. When the intervals between the ring lugs 36 coincide with the cover lugs 35, the cover 22 can be freely raised and lowered. When the cover 22 has been lowered and seated properly, a comparatively short fractional turn (about 45) of the ring 33 looks the cover and clamps it tightly against the gasket 21.

As shown in Fig. V, the cover lugs are reduced on a gradual slope 37 back from their initially engaging corners, to give a wedge action for progressively drawing down the cover 22, as well as to facilitate initial engagement with the ring lugs 36,-which are similarly reduced at 38 (to a less extent) for a like purpose. The pitch of the threads by which the ring 33 is engaged with the neck 18 gives a similar action, which may be either cumulative with that of the lugs 35 or differential therewith, according to the direction of slope in relation to the character (right or left) of the screw-threads. As shown, there is an upstanding pin 33 on the cover 14, to serve as a stop for one of the handles 34 when the locking ring 33 is in an unlocked position. However, if a degree turn away from this stop 38 does not (for any reason) really seat the cover 22 and compress the gasket 21 sufliciently, then the ring 33 may be turned still further away from the stop, past another unlocking position and into another locking position, etc., as may be found necessary.

It will be seen that this manhole construction saves both space and weight as compared with old styles of manhole. As its gaskets 20, 21 are in grooves, and as the covers 14, 22 do not rotate or rub on them in closing or opening, these gaskets will last much longer than the usual flat gaskets. There are no stufiing boxes to leak, as for other quick opening filler plugs with spindles through them. Not only can be filling cover 22 be easily and quickly opened and closed, but the main cover 14 can also be very easily removed and returned and secured again, by merely unscrewing and screwing on the nuts 25.

Having thus described my invention, I claim:

1. A manhole construction comprising a band or frame adapted to be secured in an opening in the wall of a tank and having openings therein inside the tank, a cover seated onsaid band, and cover-securing bolts with headed ends hooked into said openings and behind their edges, so that the bolts cannot be released without unscrewing.

2. A manhole construction comprising a band or frame adapted to be secured in an opening in the wall of a tank, a cover provided with a gasket at its lower side seated on the upper edge of said band, and having therein an opening surrounded by an upstanding externally screw-threaded flange provided with an upward-exposed gasket, anchor bolts for said cover secured to said band and extending up inside the same through said cover around its said flange, a cap for said cover opening seated on said gasket and having inward extending locking lugs at its lower side, and a locking member screwed on said flange having external locking lugs for engaging the locking lugs of said cap.

3. A manhole construction comprising a band or frame adapted to be secured in an opening in the wall of a tank, and having notches in its lower edge, a cover seated on the upper edge of said band, and having therein an opening surrounded by an upstanding externally screwthreaded flange, hook bolts for securing said cover engaged in said notches and extending up inside said band through said cover, a cap for said cover opening seated on and overhanging said cover flange, and a locking ring screwed on said flange cooperating with the overhanging margin of the cover and having an operating arm adapted to move between the same and the heads of said bolts when the ring turns.

4. A manhole construction comprising a band or frame adapted to be secured in an opening in the wall of a tank, and having notches in its lower edge, a cover seated on the upper edge of said band, and having therein an opening surrounded by an upstanding externally screw-threaded flange, hook bolts for securing said cover engaged in said notches and extending up inside said band through said cover, a cap for said cover opening seated on and overhanging said cover flange, and a locking ring for said cap screwed on said flange and thus rotatable to secure and release the cap, and also adjustable in height on the flange to assure proper seating of the cap when secured by said locking ring.

5. A manhole construction comprising a band or frame adapted to be secured in an opening in the wall of a tank, and having notches in its lower edge, a cover seated on the upper edge of said band, and having therein an opening surrounded by an upstanding externally screwthreaded flange, hook bolts for securing said cover engaged in said notches and extending up inside said band through said cover, a hinged cap for said cover opening seated on and overhanging said cover flange, and having inward extending locking lugs at its lower side, and a locking ring screwed on said flange having external locking lugs for engaging the locking lugs on said cap when the ring is rotated in one direction and thereby forcing the cap into engagement with the said cover flange.

JAMES A. JENSEN. 

